That's one end of the lead screw.

Typically, an electric motor is mechanically connected to rotate a lead screw.

Therefore, when the lead screw is rotated, the nut will be driven along the threads.

Most electro-mechanical designs incorporate a lead screw and lead nut.

Since the motor moves in a linear fashion, no lead screw is needed to convert rotary motion to linear.

The lead screw is in turn linked to the gantry or milling head by a special precision machined connection assembly.

The rotation of such a lead screw may be controlled either manually or by a motor.

A single soundhead was attached to a lead screw.

A split nut assembly is often used in positioning systems, for example in the lead screw of a lathe.